Ex Parte Cisar et al

Board of Patent Appeals and Interferences

Jul 31, 2007

10175515 (B.P.A.I. Jul. 31, 2007)

The opinion in support of the decision being entered today was not written
for publication and is not binding precedent of the Board.

UNITED STATES PATENT AND TRADEMARK OFFICE
__________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte ALAN CISAR and TODD ADAMS
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Appeal 2007-2124
Application 10/175,515
Technology Center 1600
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Decided: July 31, 2007
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Before DEMETRA J. MILLS, LORA M. GREEN, and RICHARD M.
LEBOVITZ, Administrative Patent Judges.

LEBOVITZ, Administrative Patent Judge.

DECISION ON APPEAL
This is a decision on appeal from the final rejection of claims 1, 8-13,
19, 26-28, 36-38, and 47-52. We have jurisdiction 35 U.S.C. § 6(b). We
reverse.
STATEMENT OF CASE
The claims are directed to a rhenium-188 (Re-188) generator. Re-188
is “an excellent isotope for radiotherapeutic applications” (Specification 2).
“However, [Re-188] has a half-life of only 16.9 hours which is too short for
the isotope to be conveniently shipped, and thus means that it must be
generated at the site of use” (Specification 2). The prior art discloses several
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Application 10/175,515

approaches for generating Re-188 from the more stable We-188 isotope at
the site of use (Specification 2-4). The invention is described as providing
an Re-188 generator which contains “a matrix comprising a substantially
non-elutable inorganic layered hydroxide compound containing tungsten-
188” to generate Re-188 (Specification 4).
The Examiner relies on the following evidence of unpatentability:
Ehrhardt US 4,859,431 Aug. 22, 1989
Claims 1-53 are pending (Supp. Br. 1). Claims 1, 8-13, 19, 26-28, 36-
38, and 47-52 stand rejected under 35 U.S.C. § 103(a) as obvious over
Ehrhardt (Supp. Br. 2). Claims 2-7, 14-18, 20-25, 29-35, 39-46, and 53
“stand objected to as being dependent upon a rejected base claim but would
be patentable if rewritten in independent form including all of the base
limitations of the base claim and any intervening claims” (Suppl. Br. 2).
There are four independent claims, 1, 13, 19, and 28. Each of the
independent claims involves an inorganic layered hydroxide compound for
producing Re-188. We select claim 1 as representative. Claim 1 reads as
follows:
A rhenium-188 generator comprising an elutable container
defining an eluant flow path, the container containing a matrix
comprising a substantially non-elutable inorganic layered
hydroxide compound containing tungsten-188.

ISSUE ON APPEAL
The Examiner contends that Ehrhardt describes a tungsten compound
and a base, such as sodium hydroxide, meeting the claimed limitation of an
“inorganic layered [hydroxide] compound containing tungsten-188”
(Answer 5-6). Appellants contend that the phrase “inorganic layered
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hydroxide” as recited in claim 1 is properly interpreted as “a mixture of at
least two cations with surrounding shells of bound hydroxyl groups” as
defined in the Specification (Supp. Br. 8-9). They contend that Ehrhardt’s
tungsten compound does not have this structure (Supp. Br. 8-9).
The sole issue in this appeal is the proper interpretation of claim 1,
particularly whether the Ehrhardt’s tungsten compound is “a substantially
non elutable inorganic layered hydroxide compound” as recited in claim 1.

CLAIM INTERPRETATION
During patent examination, the words in a claim must be given their
the broadest reasonable meaning “in their ordinary usage as they would be
understood by one of ordinary skill in the art, taking into account whatever
enlightenment by way of definitions or otherwise that may be afforded by
the written description contained in the applicant’s specification.” In re
Morris, 127 F.3d 1048, 1054, 44 USPQ2d 1023, 1027 (Fed. Cir. 1997). See
also In re Crish, 393 F.3d 1253, 1256, 73 USPQ2d 1364, 1367 (Fed. Cir.
2004). With this as guidance, we turn to the interpretation of claim 1.
Claim 1 is directed to a rhenium-188 generator comprising an elutable
container containing “a matrix comprising a substantially non-elutable
inorganic layered hydroxide compound containing tungsten-188.” The
Specification describes on page 5 what is meant by an inorganic layered
hydroxide:
The insoluble inorganic layered hydroxides of the invention
comprises a mixture of at least two cations with surrounding
shells of bound hydroxyl groups, for example magnesium
aluminate and lithium aluminate.
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In view of this specific description in the Specification, we find that
the broadest reasonable interpretation of an inorganic layered hydroxide
compound is that it must be “a mixture of at least two cations with
surrounding shells of bound hydroxyl groups” (Specification 5).
Our interpretation is consistent with the usage of the phrase “layered
hydroxide” by persons of ordinary skill in the art. Appellants provided a
publication which describes “layered double hydroxides” as represented by
the general formula “[MII1-xMIIIx(OH)2]x+ [An-x/n·yH2O]x-, where M are
cations, and A is an anion (Kovanda, J. Solid State Sciences, 5: 1019-1026
(2003) at p. 1019). This formula of a layered hydroxide has at least two
cations with surrounding hydroxyl (OH) shells. This prior art definition is
similar to the formula of magnesium aluminate shown in the instant
Specification, e.g., Mg(2n)Aln(OH)4Zn·mH2O (Specification 6). See also
Specification 7 for the formula of lithium aluminate.
THE PRIOR ART
Ehrhardt
1. Ehrhardt describes a process for preparing a tungsten-188 (W-188) /
rhenium-188 (Re-188) generator (Ehrhardt, Abstract).
2. The generator comprises a tungstate matrix containing W-188 producing
by irradiating tungsten-186 (Ehrhardt, Abstract).
3. Tungsten-186 trioxide (WO3) is irradiated to produce W-188 (Ehrhardt,
col. 3, ll. 49-51).
4. The irradiated tungsten trioxide is dissolved in a basic solution (Ehrhardt,
col. 3, ll. 52-55).
5. “The base may be sodium hydroxide, potassium hydroxide, ammonium
hydroxide or a similar source of hydroxyl ion” (Ehrhardt, col. 3, ll. 56-58).
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6. The basic solution is combined with an acid solution containing zirconyl
ion to precipitate the zirconyl tungstate matrix (Ehrhardt, col. 3, ll. 24-27
and 60-68).
7. “It is preferable to slowly add the basic tungsten solution to the acid
solution . . . to promote formation of zirconyl tungstate. This is because of
the tendency of the zirconyl cation to form zirconium hydroxide” which is
undesirable (Ehrhardt, col. 4, ll. 5-12).
8. After the zirconyl tungstate matrix is precipitated, the pH of the slurry
comprising the matrix is adjusted to from 5 to 7 using a base such as sodium
hydroxide to prevent the zirconyl tungstate from re-dissolving (Ehrhardt,
col. 4, ll. 19-23).
9. “Any zirconium hydroxide which forms from the excess zirconyl cation
used as described above, may precipitate when the slurry is adjusted to a
basic pH. This precipitate may remain associated with the matrix and adsorb
any solubilized tungsten released from the matrix which would otherwise
contaminate the eluate” (Ehrhardt, col. 4, ll. 23-29).
10. The matrix material may be transferred to an empty container, such as a
glass column used in standard chromatography, for eluting and harvesting
the daughter compound Re-188 (Ehrhardt, col. 4, ll. 40-47).

DISCUSSION
The dispute in this appeal turns on the proper interpretation of the
phrase “inorganic layered hydroxide.” The Examiner contends that Ehrhardt
teaches a tungsten compound which contains hydroxide, meeting the
limitation in claim 1 of an “inorganic layered hydroxide” (Answer 3-4).
Appellants assert that the Examiner improperly interprets the claimed
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“inorganic layered hydroxide compound” to read on the tungsten compound
described in Ehrhardt (Suppl. Br. 8-9). We agree with Appellants that the
Examiner has not given the words in claim 1 their broadest reasonable
interpretation.
The Examiner argues that Ehrhardt’s teaching of tungsten trioxide
dissolved in a base, such as sodium hydroxide or a similar source of
hydroxyl ions (Answer 5-6; Ehrhardt, col. 3, ll. 52-58; Findings of Fact 4, 5)
would have been recognized by the person of ordinary skill in the art as an
“inorganic layered hydroxide compound containing tungsten-188” (Answer
6).
The Examiner appears to have presumed that any tungsten-188
compound comprising a hydroxide is an inorganic layered hydroxide.
However, we have interpreted the claimed compound in view of the
Specification and its ordinary usage by persons of skill in the art to require a
specific structure: a mixture of at least two cations with surrounding shells
of bound hydroxyl groups. The Examiner does not explain how Ehrhardt’s
tungsten trioxide solution, or any other tungsten compound disclosed in
Ehrhardt, meets this limitation or could be modified to meet it.
Ehrhardt makes no mention of inorganic layered hydroxides. It is the
Examiner’s burden to provide reason to believe that the claimed subject
matter may be an inherent characteristic of the prior art. See In re Thrift,
298 F.3d 1357, 1365, 63 USPQ2d 2002, 2007 (Fed. Cir. 2002); In re
Schreiber, 128 F.3d 1473, 1478, 44 USPQ2d 1429, 1432 (Fed. Cir. 1997); In
re Swinehart, 439 F.2d 210, 213, 169 USPQ 226, 228 (CCPA 1971). In this
case, it is the Examiner’s burden to provide evidence or some logic to
explain why it is reasonable to presume that Ehrhardt’s tungsten compound
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in combination with sodium hydroxide is an inorganic layered hydroxide.
Because no evidence has been provided, we find that the Examiner failed to
meet his burden in establishing that Ehrhardt’s tungsten compound satisfies
the claimed limitation of an inorganic layered hydroxide.
Ehrhardt also teaches that, in acidifying the basic tungsten trioxide
solution with an acid solution comprising zirconyl ions, zirconium
hydroxide may form and “remain associated” with the zirconyl tungstate
matrix (Ehrhardt, col. 3, ll. 24-27 and 6-68; col. 4, ll. 5-29; Findings of Fact
6-9). Once again, we find no evidence in the record to provide a reason for
believing that the zirconyl matrix comprising zirconium hydroxide has the
specific structure of an inorganic layered hydroxide compound as required
by claim 1.
Furthermore, the Examiner has also given no reason for persons of
skill in the art to have modified Ehrhardt’s compound to produce a inorganic
layered hydroxide in the scope of the claim. See KSR Int’l Co. v. Teleflex
Inc., 127 S.Ct. 1727, 1741, 82 USPQ2d 1385, 1396 (2007) (Obviousness
requires a “a reason that would have prompted a person of ordinary skill in
the relevant field” to have modified the prior art “in the way the claimed
new invention does.”)

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Application 10/175,515

We reverse the rejection of claims 1, 8-13, 19, 26-28, 36-38, and 47-
52.
REVERSED

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